Refrigerating apparatus



July 6, 1937. G. F. WEIHER 2,086,485

REFRIGERATING APPARATUS Filed March 17, 1936 I3 I I so 1 N VEN TOR. 6:00a: f: Wen/me.

HIS ATTORNEYS.

50 noise caused thereby will bhbiectionable. Ap

Patented July 6, 1931 UNITED sTAT s PATENT or-rice poration of DelawareApplication March 17, 1936, Serial No. 69,359

2 Claims.

. vThis invention relates to compressors of refrigerating systems andparticularly-to a valve arrangemen therefor.

An objecg of the present invenfim is to provide an 'im oved compressorfor a refrigerating system. i

Another object of thepresent invention is to provide 'a valvearrangement onor within the piston of a compressor which will operateefllciently and quietly in order that the compressor in which the valvearrangement is incorporated may be used in refrigerating apparatus ofthe household type.

A further object of the present-invention is to provide a valvearrangement in or on the piston of the compressor of a refrigeratingsystem which will be of increased structural strength and longlife.

In carrying out the foregoing objects itis a still further and morespecific object of the invention to provide a piston for acompressor ofa refrigerating system which hasa part movable relative to anotherpartthereof and forming a complementary part of certain of theperipheral walls of the piston and which movable part of thepiston/forms a valve for sealing a passage or passages extending throughthe piston. Further objects and advantages of the present invention willbe apparent from the following desystem diagrammaticallyconnected-to thecom- )7 scription, reference being had to the accompanying drawing,wherein a preferred form of the present invention is clearly shown. Inthe drawing: g

Fig. 1 is a, sectional view of a compressor of a refrigerating systemhaving the present invention embodied therein andshowing therefrigerating pressor; A 7

Fig.2 is an enlarged vertical sectional view of 4 the piston of thecompressor shown in Rs. 1 having my invention incorporated th r i 1-Fig. 3 is an enlarged fragmentaryvertical sectional view of a pistonwithin ficyunfler of the compressor shown inFlg. 1.

Reierr ng to the drawing 'for -mn t u present vention, I have shown arefrigerating system of the type suitable for' 'in'stallation'in'smallrefrigerators of the household variety. This type of apparatus isusuallyinstalled in cabinets which are placedin localities wher paratusof this type must be automatic in op"- eration and such operationthereof mugtb ried outquietly. The apparatus or system may' comprise acompressor. generally'represented by 1 Operation of motor l6 tries 24and 25 mounted thereon for operating above the cylinders together withthe the reference character It, discharging refrigcooled and liquefiedin condenser I! in any suitable or conventional manner and flows into achamber I3 containing a float or otherwise 0perated valve which controlsthe flow of liquid refrigerant to the evaporator ll. Refrigerantvaporized in evaporator I4 is drawn through a conduit l5, by suctioncreated by the compressor l0; back to the compressor preferably to thecrankcase thereof. The evaporator I4 is adapted to be mounted within aninsulated compartment of a refrigerator cabinet (not shown) from whichheat is to be extracted. Means for controlling a. motor I6which operatesthe compressor ll, through suitable beltand pulley connections ,inresponse to the temperature pro-' duced by the evaporator l4 may beprovided. This. means may comprise an expansible bellows I! connected bya; pipe H to a bulb 2i, mounted in thermal association with theevaporator I4,

and having a volatile fluid sealed therein for actuating, upon movementof the bellows It, a

switch 22 interposed in the powerJine leading 25 to motor [8; a

drives the compressor shaft 23 through the connections l'l. Rotation of.compressor shaft 23 causes rotation of eccenthe pltmans 26 and 21respectively to cause the 30 "compressor pistons 28 to be reciprocatedwithin the cylinders 28. The end of the shaft 23 which extends throughawall of the compressor crankcase-may be sealed by any suitable orconventional sealing means generally indicated at 8|. Outlet checkvalves 3!, which may be of the type fully disclosed in the Patent No. 1851203 to Otto M. summers on April 5, 1932, mounted within thecompressor I. upon a suitable plate refrigerant flow control means Itdivide the refrigerating system into a low pressure portion and a highpressure portion. The low pressure. portion of the refrigerating systemthe evaporator ll, conduit I and the of compressor ll. V i" The valvearrangement in the present disclosure employed to intermittently openand close the passag extending through the pistons -20 and whichpassages establish communication be-' tween the crankcase of compressorII and the cylinders 28 will now be described. erring to Figs. 2 and'3it wlll be noted that the istons 2| head includes a tapered wall surface36 and a straight side walled portion 31 formed th reon. A raisedportion 38 extending cohtinsdgsly. around the tapered wall surface 38provid a seat for the valve arrangement. Any desired number of holes 39may be cut or bored through the wall of head 35 of piston 28 preferablysubstantially at right angles to and within the boundary of the raisedportion 38 extending around the tapered surface 36. These holes 39provide the passage through the .piston 28 for the flow of fluid fromthe compressor crankcase for the reception of a-locking or securingmeans to be presently described. In order to eliminate the usual springpressed valve or valves and the hke from the con'struction of the'piston2 8 I provide a collarlike rim member 42 which surcompressor crankcasewith. the cylinders above the piston 28; Thus thecollar member 42 servesrounds the head 35 of piston 28 and forms a complementary part of thepiston. and particularly a complementary part of certain peripheralwalls thereof. It will be noted that this collar member 42 includes a.tapered wall portion 43 which registers with the raised surface 38formed on the tapered wall portion 36 provided on the piston head 35.Collar member 42 also includes a skirt portion 44 which surrounds andregistersfwith the straight sidewall portion 31 providedon the head 35of piston 28. This complementary collarlike part of piston 28 may carrya. conventional piston ring indicated at 45 and adapted to bear againstthe wall of cylinder 29. The collarlike member 42 has a groove 46 cut inthe inner surface of the skirt portion 44 thereof and it will be notedthat this groove 46 is wider than groove 4| provided in the piston head35 for a purpose to be presently described. An expansible ring 48similar in construction to a conventional piston ring islocated ingrooves 4| and 48 and. this ring forms the lockingfmeans for securingthe complementary collarlike portion 42 of piston 28 to the headthereof. In assembling the member 42 upon the head 35 of piston 28 thering 48 is compressed within groove 4| to permit the mner wall surfaceof the skirt'portion '44 of collar member 42 to slip down over the ring48. The spring tension of .ring 48 will cause expansion thereof intogroove'46 when this groove is moved it at any time be necessary toremove the collar member 42 from piston 28. It will be seen from theforegoing that the raised surface 38 of the tapered portion 36 of pistonhead 35 forms a seat. for the tapered surface-43 provided on the collarmember 42 and that the collar member 42 forms a means adapted to closethe fluid passage,

openings'39, which permits communication of the as a valve forcontrolling the flow of fluid from one side'to the other ofthe pistonand this memtop surface of the piston 28 so asto form a flat continuoussurface entirely across the interior of the cylinder 29 to insure thatwhen the pigton is in its uppermost position all fluid compressed withinthe cylinder' will be discharged therefrom. In accordance with theforegoing described construction it .is obvious that the collar member42 serves as a valve and also forms a complementary part of certainperipheral wall surfaces of the piston.

In the operation of compressor, 8, by motor IS, the pistons arereciprocated and suction created in cylinders 29 by the initial downwardmovement of the 'piston therein causes the collar member of the piston,which formsthe piston valve, to be elevated relative to the other partof the piston as shown in Fig. 3 of the drawthe port holes 39, nowuncovered by the collar member portion 42 of the piston, intothecylinder above the piston. When the piston reaches its lowermostpoint of reciprocationand begins its upstroke the collar member part 42thereof moves toward the main body portion 28 of the piston and thetapered surface 43-of collar 42- abuts against the raised portion 38 ofthe tapered surface 36 provided on the piston head 35 to close or sealthe port holes 39. Refrigerant fluid drawn into cylinders 29is trappedtherein between the top of piston 28 and the outlet check valve 32.Further upward movement of piston 28 compresses the refrigerant fluidand forces same under pressure through the outlet opening at the top ofcylinder 29, controlled by check valve 32, through conduit II and intocondenser l2.

From the foregoing itwill be apparent that I have provided an improvedvalve construction for compressors which is quiet in operation andcapable of operating for a long period of time. .By making the improvedvalve construction as a-complementary part of the compressor piston thevalve is of increasedstructural strength and this valve does not impairor reduce the efliciency of the compressor since same forms acontinuationof the. top and side peripheral walls of the piston andtherefore provides a construction which insures thatsubstantially allfluid drawn 'into the cylinder above the piston will be comw pressed inand expelled from the cylinder. My improved valve constructioneliminates a certain amount of trouble ordinarily encountered in the useof compressors employing. thin disk valves or-the like which arefrequently out beyond repair or are broken by engagement thereof withthe seat under high pressure conditions.- The improved construction alsoeliminates the use of a spring or springs forforcin'g the valve intoengagement upon its seat and this reduces parts to a minimumas well aseliminating trouble which is frequently caused by breaking of suchsprings.

While the form of embodiment ofthe invention as herein disclosedconstitutes a preferred form, it is to be understood that otherformsmight be adopted, all coming within the scope of the claims which followWhat is claimed is as follows: 1. In combination with a piston adaptedto be reciprocated within a cylinder of a compressor and having apassagetherethrough for conveying a fluid from one side of the pistoninto the cylinder on the opposite side thereof, said pisthe head thereofand opening into said angled piston head wall surface, a memberincluding an angled wall surface corresponding to and registering withthe angled wall surface of said piston, said member being movablysecured to the piston to control the flow of fluid through the fluidpassage in said piston, and said member cooperating with said piston toform a complementary part of the peripheral side and top wall surfacesthereof.

smas es 2. In combination with a'piston adapted to be reciprocatedwithin a cylinder of a compressor and havinga plurality of passagestherethrough for conveying a fluid from one-side of the pis-- ton intothe cylinder on the opposite side thereof, saidpiston having a straightside wall surface and a closed top wall, the side wall surface of saidpiston being closely fltted within said cylinder for guiding sametherein, said pistonalso having a wallsurface disposed intermediate andat an angle to the top and side wall surfaces thereof and forming a headon said piston, the fluid passages through said piston being located atspaced apart points in the head thereof and opening into said angledpiston head wall surface, a collar including an angled iiiner .wallsurface corresponding to and registering with the angled wall surface ofsaid piston said collar being movably secured to the piston to controlthe flow of fluid through the fluid passages in said piston, and saidcollarcooperating with said piston to form a complementary part of theperipheral side and top wall surfaces thereof. GEORGE F. WEIHER.

